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Front panel power LED doesn't turn on everything else OK

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  • Front Panel
  • Motherboards
  • Power
Last response: in Components
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July 21, 2014 4:06:19 PM

Everything seems to be working fine so far (Haven't installed Windows yet) except the front panel power LED does not work properly. The HDD activity LED, power button, USB ports, and the rest of the front panel seem to work fine, but when I turn on the PC the power LED doesn't come on. However, this is very strange to me because when I first booted I accidentally had the power button pins in upside-down and the light came on and still does in that arrangement, so I know for sure it is not dead. I cleared the CMOS and that didn't solve it. Any suggestions?

More about : front panel power led turn

a c 84 V Motherboard
July 21, 2014 4:09:56 PM

make sure you plugged the wires in to the proper places. make sure you have teh positive and negative wires plugged in to the proper pins.
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July 21, 2014 4:20:03 PM

bgunner said:
make sure you plugged the wires in to the proper places. make sure you have teh positive and negative wires plugged in to the proper pins.


They look to be plugged in correctly (- with -/+ with +). Tried them upside down too and nothing.
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a c 84 V Motherboard
July 21, 2014 4:33:14 PM

well next you will need a multimeter to test with. First test the pins to see if they are putting out any voltage. Then test the led Ohms to see if there is any continuity between the wires. This will tell you if the led is good.
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July 21, 2014 4:47:53 PM

bgunner said:
well next you will need a multimeter to test with. First test the pins to see if they are putting out any voltage. Then test the led Ohms to see if there is any continuity between the wires. This will tell you if the led is good.


I don't have one with me right now, but I do know the LED is good because like I said when the "power sw" pin is upside-down the light comes on, so this makes me think the motherboard won't send any voltage to the LED, but I'm not sure why.
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a c 84 V Motherboard
July 21, 2014 5:06:05 PM

what do you mean the power switch pin is upside down?
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July 21, 2014 5:25:45 PM

bgunner said:
what do you mean the power switch pin is upside down?


The 2 pin connector to the front panel power button only works properly with the label facing up, not facing down. With label facing up the power led does not come on and when facing down the light works, but causes the power button to malfunction in other ways.
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a c 84 V Motherboard
July 21, 2014 5:38:58 PM

Sounds like a bad connection or wrong pins. Lets look at the Power switch. The switch itself consists of a 2 wires 1 spring and 1 small strip of metal. When the power button is pressed it pushes on the metal strip forcing it to make contact with both the wires ( this is an over simplified explanation). WHen the 2 wires ate connected to each other it shorts the positive and negative pins together, the same can be done in the case with a screw driver or paperclip even, when this happens the system turns on or off.

the LED can be pole sensitive. They need to be positive to positive and negative to negative for them to work properly.

If the switch wires are connected, no matter what the poles are the switch will work. The LED's on the other hand are a different story. If you flip the switch plug over and there is an issue then look at teh plug itself to start with being an issue. the connectors in plastic plug may not be making proper contact with the pins.
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July 21, 2014 6:09:21 PM

bgunner said:
Sounds like a bad connection or wrong pins. Lets look at the Power switch. The switch itself consists of a 2 wires 1 spring and 1 small strip of metal. When the power button is pressed it pushes on the metal strip forcing it to make contact with both the wires ( this is an over simplified explanation). WHen the 2 wires ate connected to each other it shorts the positive and negative pins together, the same can be done in the case with a screw driver or paperclip even, when this happens the system turns on or off.

the LED can be pole sensitive. They need to be positive to positive and negative to negative for them to work properly.

If the switch wires are connected, no matter what the poles are the switch will work. The LED's on the other hand are a different story. If you flip the switch plug over and there is an issue then look at teh plug itself to start with being an issue. the connectors in plastic plug may not be making proper contact with the pins.


This is my problem is confusing. The pins in the switch appear to be making good contact, but I tried it again and these are the problems (LED pins are inserted correctly in both scenarios):

Power switch label side up - LED does not come on

Power switch label side down - LED comes on, Computer boots as soon as the switch on the power supply is turned on, front panel power switch will turn the computer off once, but not back on (neither will the button on the motherboard)

As you can see my system seems to work better with the power switch in one way over the other. I have no idea why though. Either way, I don't understand why this affects the led from turning on.
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a c 84 V Motherboard
July 21, 2014 6:19:04 PM

Is it really that important to have the Power led? I can see having it if there were no other LED's in the case. Because the switch, with label down, turns the PC on right away this tells me there is a short somewhere. Is the power led in the switch?
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July 21, 2014 6:30:22 PM

bgunner said:
Is it really that important to have the Power led? I can see having it if there were no other LED's in the case. Because the switch, with label down, turns the PC on right away this tells me there is a short somewhere. Is the power led in the switch?

Of course it's not necessary to have it, but it would be nice to have it work how it is designed too. The led is in the power button. My case is the Corsair 500R and motherboard is Asus Z97 Pro wifi if that helps.
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a c 84 V Motherboard
July 21, 2014 6:37:05 PM

The LED in the button is the issue. Is this case new? If so it wouldn't hurt to get a hold of corsair and ask for a new switch. I'm wondering if they installed teh led in the switch upside down, backwards how ever you want to put it.
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July 21, 2014 6:57:19 PM

bgunner said:
The LED in the button is the issue. Is this case new? If so it wouldn't hurt to get a hold of corsair and ask for a new switch. I'm wondering if they installed teh led in the switch upside down, backwards how ever you want to put it.


Okay. I guess that's what I'll have to do if I can't get it working. Thanks for the assistance.
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